活性炭

1. Origins, structure, and basic meaning

• Structure: 活性炭, read かっせいたん, is activated carbon, an adsorbent carbon material used in purification and odor control.
• Basic usage: It names the material replaced in a water purifier or used in an experiment that observes changes in odor.

2. Common pitfalls and similar expressions

• A material used in purification
  • This refers to activated carbon replaced in a water purifier or used in an odor experiment. It should not be broadened to mean every kind of ordinary charcoal.